A common embodiment of such an apparatus for catalytic cleaning of waste gases consists of a regenerative heat exchanger, a heating unit, an ammonia supply unit and catalysts, through which the raw gas is directed in sequence after having left the power station. The cleaned gas leaving the catalysts is routed again through the heat exchanger and finally escapes from the apparatus. Stated more precisely, the raw gas to be cleaned is first preheated in the regenerative heat exchanger, whose heat transferring surfaces are heated up by the cleaned gas coming out from the catalysts and is subsequently conducted to the heating unit, in which it is heated to the operating temperature of the catalysts. Ammonia is added to the raw gas via the ammonia supply unit, after it has passed through the heating unit and then, after a thorough mixing, the gas reaches the catalysts, where it is de-nitrified. The cleaned gas, leaving the catalysts, is then conducted through the regenerative heat exchanger, thereby heating up the heat transferring surfaces, and finally leaves the apparatus.
It is always desirable to advantageously modify a common apparatus.
It is therefore an object of the present invention to provide an apparatus for catalytic cleaning of waste gases, which has a smaller overall size in comparison to the conventional ones and which requires a lesser amount of external energy for its operation.
This object is fulfilled through an apparatus for catalytic cleaning of waste gases according to the present invention.